Thomas w



T.l wqnouH AND w. F. MINOR.

LIGHTING FIXTURE.

APPLICATION FILED MAY |51 1916.

1,304,378, `Patented May 20, 1919.

Inventors Thomas W. Rolphv, Wlliam Frost minor,

UNITED STATES PATENT oEEroE;

THOMAS W. ROLPH AND WILLIAM ROSVT MINOR, CLEVELAND, OHIO, ASSIG-NORS T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

i LIGHTING-FIXTURE.

Specification of Letters Patent.

Patented May 20, 1919.

Application med may 16, 191e. serial No. 97.799.'

To all whom #may concern.'

. Be it known that we, THoMAs W. RoLPrr and WILLIAM FROST MINOR, citizens of the United States; both residing at Cleveland, county of Cuyahoga, State of Ohio, have invented certain new and useful Improvements in Lighting-Fixtures, of which theI following is a specification.-

Our invention relates to a totally inclosed v,electric light fixture particularly adapted to the housing `of a high efficiency tungsten lamp. A

The direct rays from a concentrated source of light, as the high efficiency tungsten lamp, are highly intense and discomforting to the eyes. One object of our invention is to avoid all glare by diffusing and softening or totally shielding these direct rays without at the same time i-mpairing the efficiency of the transmissionc and distribution of the light as4 a -who1e,and we accomplish this by incorporating in the globe and interposing in the path of the rays which ordinarily strike the eye a diffusing or softening glass, the other parts of the globe preferablybeing of a glass less dense and more transparent for eiiiciently transmitting the light to the areas to be illuminated. More specifically, our globe embodies three distinct and separate parts, all fitting into each other to form a totally inclosed globe with zones lof glass varying in density. The middle section or zone is of sufficient density tosoften and diffuse the direct rays comfortably to the eyes, while the lower section and the upper section are preferably more transparent for efficiently illuminating wide areas both be- 'low andabove the fixture.

The multipart or zone feature of our globe is important in contributing toeasy assembly, the various sections belng readily brought together to form a dust proof inclosure. Sections of different designs may be provided and easily substituted to change the appearance of the globe, and the globe as a whole is not rendered useless by the breaking of a section, inasmuch as the broken `zone'may bereplaced by a new one with facility. A V

The preferred embodiment ofour invention is illustrated in the drawing accompa- .nying this specification, wherena high eiciency tungsten lamp 1 is shown' as housed in our improved inclosure. The lamp socket is illustrated as fitting in the' usual manner @to the neck of the upper part or .dome 2 of our globe. The middle section or zone 3 has on its upper periphery an annular groove for. receiving in-a dust proof manner the skirt of the dome 2 and the ring 4 is attached 60 to the upper edge of the middle section, being supported from the ceiling by chains 6. Before the parts 2 and 3 are assembled, however, a bowl 5 is lowered through the top of zone 3 into engagement with the lower periphery, an annular curved bearing surface on the zone coperating with a similar surface on the rim o-f the bowl to form a dust proof joint.

The density of the glass of Zone 3 should be suflicient to 5comfortably diffuse and soften the rays lpassing therethrough, and the zone should be wide eno-ugh and of a conf formation to intercept the rays that ordi# narily strike the eye of an observer in approaching. With the particular dimensions and shape illustrated, these softened `and subdued rays are embraced within the angle A-B-C, the angle of the diffused light below the horizontal plane passing through B being greater` than that above the plane. This particular arrangement lends itself to a proper distribution of the light as a whole, the dome 2 and bowl 5 preferably being of a glass of lower density and more transparent than Zone 3 for freely transmitting the light in the upwardiand downwardI directions. y What we claim and desire tosecure by Letters Patent of the United States, is:

l. An outer globe particularly adapted for housing a high efficiency tungsten lamp comprising a lower section and an upper section in combination with a middle section extending from the lower edge of said upper section to the upper edge of said lower section and composed of a denser and less transparent medium than either of the other sections. t

2. An outer globe particularly adapted for housing a high efficiency tungsten lamp comprising a dome section, a bowl section and an intermediatesection extending from the lower edge of said'dome section to the -upper edge of said bowl section and comprisingA a transparent dome, a transparent bowl, and a middle zone of a softening and diffusing glass, the three sections fitting into each other to form a totally inclosing globe.

4. In a lighting fixture, the combination of a high efficiency tungsten lamp With a three part totally inolosed globe Comprising a transparent dome, a transparent bowl,

ing a high eficienoy tungsten lamp comprising a middle zone of a diffusing glass With means for suspending same in combination with a bowl and a dome carried by and l itting into said middle zone to form a t0- tally inolosing globe.

In Witness whereof, We have hereunto set our hands this 11th day of May, 1916.

THOMAS W. ROLPH. V WILLAM FROST MlNOR. 

